1. Field of the Invention
The present invention relates to a railroad hopper cars, and more particularly to the side and door structures for an open top hopper railcar.
2. Background Information
A hopper railcar, or hopper car, is a railcar used to transport loose bulk commodities such as grain, coal, minerals, fertilizers, cement, etc. The hopper car interior is typically divided into pockets or hoppers with doors on the bottom of each pocket to empty cargo by the force of gravity, making for quick and effective unloading. The discharge doors do not prevent the use of a rotary unloader that pivots the entire car, but the discharge doors on the bottom do not require the use of such a rotary unloader.
Further the hopper railcars may be closed hopper railcars or open top railcars that are easy for top loading. Even with “open top” hopper railcars, removable covers can be used for transport and other specialized tops could be used with a hopper railcar depending upon the intended cargo.
Closed railway hopper cars with pneumatic systems for unloading are often used for the transportation of powdered and granular products. For cars with positive pressure pneumatic systems, air may be supplied from an external source to pressurize the interior of the car body and simultaneously fluidize the dry, bulk product carried within the car to enable it to be conveyed in a fluidized state through product transfer conduits from the car to a collection facility. Air pressure within the hopper car during unloading is typically maintained at approximately fifteen pounds per square inch gauge pressure.
The present invention is primarily related to open top hopper cars, but certain aspects of the invention may be used in other car types. The following is a brief discussion to establish the state of the art in open top hopper railcar and door operating systems.
U.S. Pat. Nos. 144,966; 147,341, 162,189; 217,289; 347,523; 349,134, 369,102; 500,846; 528,279; and 568,775 from about 1873-1889 disclose early proposed hopper railcar designs, which is helpful to illustrate the basic hopper concepts and to better demonstrate hopper car evolution.
U.S. Pat. No. 658,783 discloses early hopper car construction with the body formed of metal sheets coupled together.
U.S. Pat. No. 699,820 discloses a general hopper car and specifically a door operating mechanism for a hopper car, also called a “dumping car” therein.
U.S. Pat. No. 743,501 discloses a hopper car and specifically an ore carrying car design.
U.S. Pat. No. 763,186 discloses a general hopper car and specifically a door operating mechanism for a hopper car, also called a “dumping car” therein.
U.S. Pat. No. 797,341 discloses a reinforced central hopper type hopper car.
U.S. Pat. No. 881,884 discloses a general hopper car and specifically a door operating mechanism for a hopper car, also called a “dumping car” therein.
U.S. Pat. No. 891,325 discloses a general hopper car and specifically a hopper lining for an ore car.
U.S. Pat. No. 914,242 discloses a general hopper car also called a “dump car” therein.
U.S. Pat. No. 937,419 discloses a general hopper car also called a “dump car” therein.
U.S. Pat. No. 1,182,642 discloses a general hopper car also called a “dump car” therein.
U.S. Pat. No. 1,300,959 discloses a general hopper car also called a “hopper dump car” therein, which shows the beginnings of multiple hoppers and distinct transverse doors for the individual hoppers, that is most common today.
U.S. Pat. No. 1,418,907 discloses a general hopper car and specifically a door operating mechanism for a hopper car, also called a “dump car” therein.
U.S. Pat. No. 1,444,730 discloses a general hopper car and specifically a door operating mechanism for a hopper car, also called a “hopper bottom” therein.
U.S. Pat. No. 2,079,862 discloses a general hopper car and specifically a center-sill design for use therein.
U.S. Pat. No. 3,080,829 discloses a ballast hopper car and specifically a ballast distributing hopper car.
U.S. Pat. No. 3,104,623 discloses a general hopper car and specifically a door locking structure for a hopper railcar.
U.S. Pat. No. 3,187,684 discloses a general hopper car and specifically a door opening system for a hopper railcar.
U.S. Pat. No. 3,242,878 discloses a “shallow” hopper car design.
U.S. Pat. No. 3,256,836 discloses a general hopper car and specifically a door opening system for a hopper railcar.
U.S. Pat. No. 3,348,501 discloses a general hopper car and specifically a sliding door opening system for a hopper railcar.
U.S. Pat. No. 3,509,827 discloses an aluminum body hopper car.
U.S. Pat. No. 3,577,932 discloses a hopper car and specifically a door opening system for a hopper railcar.
U.S. Pat. No. 4,228,742 discloses a hopper car, also called a “vehicle hopper” therein, having longitudinally spaced hopper end slope sheets and hopper cross ridge slope sheets formed prior to assembly.
U.S. Pat. No. 4,292,898 discloses a hopper car including an elongated, load bearing body having walls formed of a specified fiber reinforced plastic resin composite of glass reinforcing filaments and a structural “organo-polymeric” resin.
U.S. Pat. No. 4,361,096 discloses a hopper car including seals to prevent seepage of a fine granular commodity between the hopper doors and the adjacent hopper sheets of a railroad hopper car of the type having opposed pairs of hopper doors swingable between a closed position and a downwardly depending open position. The seals comprise elongated strips of flexible material with their upper longitudinal edge portions mounted along the inside lower edges of the inner and outer hopper sheets and being of a width such that their free lower longitudinal edge portions extend downwardly beyond the lower edges of the hopper sheets. The free edge portions of the seals being bent inwardly by and lying in sealing engagement against the hopper doors when the hopper doors are in their closed position. Similar strips of flexible material may be so located as to form a seal between the upper portion of each hopper door and its adjacent slope sheet.
U.S. Pat. No. 4,366,757 discloses a hopper railcar apparatus for actuating and locking each pair of hopper doors of a railroad hopper car of the type having a plurality of hopper doors arranged in opposed pairs and extending transversely of the hopper car center sill.
U.S. Pat. No. 4,376,542 discloses a gasket structure for application to a hopper car door edge comprises an elongated flexible gasket of compressible material having a relatively thick body with a continuous tangentially projecting rib and a plurality of narrow elongated spring clips extending transversely of the gasket and each having a straight end portion underlying the gasket and riveted to the rib thereof, a straight intermediate portion angularly disposed with respect to the straight end portion, and an opposite end portion curved in the opposite direction with respect to the intermediate portion from the angulation of the straight end portion to form a nearly closed loop, the straight end portion being adapted to engage the inner surface of the hopper door web with the intermediate portion engaging the sloping peripheral rim of the hopper door and with the opposite end grippingly engaging the outer surface of the peripheral rim to secure the gasket against the door web.
U.S. Pat. No. 4,644,871 discloses an articulated hopper railcar with a designated “short distance” between truck centers. The railcar features two bodies supported by a center truck and two end trucks, wherein the center truck takes somewhat more loading than the other two end trucks.
U.S. Pat. No. 4,884,511 discloses an aluminum body hopper railcar with having a center sill hood which uses aluminum collar castings.
U.S. Pat. No. 5,070,793 discloses a sidewall and top chord member for an open top gondola or hopper railway car developed by a predecessor in interest to the assignee. The top chord member is a lightweight rectangular tubular extrusion of aluminum having a pair of spaced wear pads on the top surface thereof to contact rotary or shaker type car unloading equipment.
U.S. Pat. No. 5,249,531 discloses actuating system for operating the doors of a railroad hopper car. A plurality of levers for each hopper operate to rotate the doors of the hopper between an open and a closed position and also provides an over center latch to positively close each door.
U.S. Pat. No. 5,417,165 discloses a railroad hopper ballast discharge door assembly includes pliant side panels along a discharge gate opening. The pliant side panels are strong enough to retain the ballast within the hopper when the door is closed, yet are flexible enough to yield when ballast flowing out of the hopper becomes wedged between the side panel and the door as the door closes.
U.S. Pat. No. 5,934,200, developed by the assignee, discloses a lightweight hopper-type rail car designed to minimize aerodynamic drag and including a cross ridge arrangement to increase the fabrication efficiency of the car.
U.S. Pat. No. 5,979,335 discloses a fully protective multi-unit railroad freight car for carrying motor vehicles on two or three levels with the lowest level being in a cargo well between a pair of deep side sills. A pair of vehicle-carrying decks are adjustable in height and are counterbalanced against each other during adjustment of their locations.
U.S. Pat. No. 6,273,004 discloses a sidewall structure for a motor-vehicle carrying railway car wherein at least one upper deck is supported principally by longitudinal beams that are themselves supported by end structures, without the need for large, heavy vertical posts to support the decks between the end structures.
U.S. Pat. No. 6,334,397 discloses side sheet construction for a hopper railcar, also called a bulk container car, side sheet assembly for a rail car having a pair of horizontally extending upper and lower side sheets form with a plurality of longitudinally extending strengthening ribs. The upper and lower side sheets are affixed to each other at a horizontal seam to either form flat connection or a rib at the horizontal seam.
U.S. Pat. No. 6,405,658 discloses a manual discharge door operating system for a hopper railcar which is provided with an over-center closed position to hold the door in the closed position.
U.S. Pat. No. 6,955,127 discloses actuating system for manually operating the doors of a railroad hopper car.
U.S. Pat. No. 7,080,599 discloses an actuating system for operating transverse doors of a railroad hopper car which close in an over center position. The mechanism includes an operating member which is coupled to a door or doors of the car by a shaft and a linkage which couples a power source to the operating member, where the operating member rotates to move the door away from the hopper. The mechanism can operate doors which open in opposed direction with a single power source. The mechanism can be used in new car construction, and can be retrofitted onto existing hopper cars.
U.S. Patent Publication 2006/0254456 discloses a general hopper railcar and a transverse door operating system with an over-center door locking or closed position.
U.S. Patent Publication 2008/0066642 discloses a general hopper railcar with seal member or seal member assembly that is mounted to one or both of the closure members. When open, the seal member or seal member assembly lies substantially flush with, or shy of, the slope of the surface of the closure member. When closed, the seal member may be self-energizing, in the sense that as lading is added the seal may tend to seal more tightly. The seal assembly may include a cantilevered spring that presents a land to the opposed closure member, and a fulcrum, over, or across, which the spring is cantilevered, such that pushing down on one end of the spring may tend to cause the other end to flex upward. The fulcrum may also be cantilevered outward from the slope sheet of the closure member to which the seal assembly is attached. The discharge section may be robustly reinforced to discourage deformation.
U.S. Patent Publication 2009/0007813 discloses a general hopper railcar with opposed double doors for discharging cargo from a hopper car.
The prior art has provided a variety of open top hopper railroad cars. The above listed patents are representative of the state of the art of hopper railcars and these patents and published applications are incorporated by reference herein in their entireties. There remains a need for sidewall structure designs that can more easily be adapted to distinct clearance profiles found in distinct jurisdictions thus increase the carrying capacity of the associated car. Further there is a need to provide for simple efficient door seal that assists to secure the doors in an over center locked position. Further there is a need to provide door designs that better accommodates end door configuration to assure complete lading discharge.